This invention relates to textile machines, and in particular to a multi-station yarn texturing machine which textures yarn by false twist crimping, a process in which at each station an untextured yarn from a supply source runs over a setting heater and through a cooling zone followed by a false twister, twist being propagated upstream of the false twister and set by the heater. In the heating zone the yarn temperature is raised close to its melting point, and in the cooling zone the yarn temperature is reduced until the yarn is sufficiently stable to withstand the action of the false twister.
In drawtexturing the feed yarn is either undrawn or partially drawn and drawing is performed or completed on the texturing machine. This can be by a separate drawing step preceding false twist crimping (sequential) or by drawing at the same time as false twist crimping (simultaneous). In so-called double-heater machines for producing set yarns to which the present invention particularly relates, the yarn runs from the false twister through a secondary heater while under controlled overfeed conditions, and is then fed to the take-up devices, so that the final product is crimped yarn of low extensibility in comparison with the so-called torque stretch yarn produced by a single heater machine.
All the foregoing is well known in the art, and it has also hitherto been proposed to positively cool the yarn in the cooling zone, rather than the yarn becoming cooler merely by its exposure to the ambient atmosphere, and prior art proposals in the patents literature have included enclosures, tubes, jackets, and contact blocks on pipes, the coolants suggested being air or circulated water or like fluid.
In known yarn texturing machines, the usual arrangement is to have packages of supply yarn on a so-called "stand-off" creel, on which the supply packages are carried in tiers and columns, the usual arrangement being that each thread-line is fed from an active supply package connected to a reserve package mounted side by side in the creel.
The creel may be a wholly fixed structure or it may be at least partially movable, for example it may comprise a fixed frame with which are associated movable sub-frames each carrying a predetermined number of supply packages.
These creels tend to be relatively high since the supply packages are large, a typical stand-off creel carrying tiers of packages in columns six high being something over 2 meters in height, so that operatives need to use mobile platform step-ladders to service both the creel and the yarn texturing machine fed by the creel.
Modern machines tend to be double-sided and have a row of texturing stations along each sside, e.g. 108 stations at each side which are supplied by respective stand-off creels with an operative's aisle between each creel and the machine.
In the constant search to increase production rates by increasing yarn throughput speeds, setting heaters and secondary heaters have become progressively longer, as well as cooling zones. Currently two meter, 2.5 meter, and three meter setting heaters are already in use along with secondary heaters of 1.45 to two meters in length.
In machines where the yarn runs downwardly through the secondary heater in a vertical path, such double-heater machines are approaching six meters in height, and as well as the obvious disadvantages which follow from such vast height, there are undesirable lengths of yarn running in uncontrolled manner from the creel to the top ends of the setting heaters. Conventionally the secondary heaters are placed behind the take-up devices and the third feed devices through which the yarns run are located beneath the secondary heaters to receive the yarns therefrom and feed them forwardly of the machine to the front of the take-up devices.
The object of this invention is to provide a yarn texturing machine of reduced height and without the disadvantage of uncontrolled running yarn lengths, but which incorporates high throughput speeds, and hence long heater and cooling plate lengths, and large diameter supply and take-up packages.
The invention provides a textile machine having a supply means for at least one yarn and in sequence for the or each yarn a first feed means, a primary heater, a cooling zone, a false twist device, a second feed means, a secondary heater, a third feed means and a take-up device, wherein said false twist device, said second feed means, said secondary heater, said third feed means and said take-up device are mounted in a common frame of said machine with said secondary heater disposed in a substantially vertical position behind said take-up device, said third feed means being located forwardly of said secondary heater and said machine comprising guide means adapted to guide said yarn from the lower end of said secondary heater to said third feed means.
The guide means may comprise a tube assembly which may provide a yarn path which is bent through substantially 90.degree.. Said tube asssembly may be detachably mounted in said machine.
The third feed means may comprise a feed roller and a nip roller forming a nip therewith through which the yarn passes. The nip roller may be disposed beneath said feed roller.
The machine may also comprise traverse means operable to traverse the yarn laterally of said nip, and said traverse means may also be disposed forwardly of said secondary heater.
By means of the invention the secondary heater may be disposed lower than was the case heretofore whilst maintaining or improving accessibility to the third feed means and the traverse means associated therewith. In consequence of the lowering of the secondary heater the second feed means, false twist device, the cooling zone and the primary heater may all be lowered relative to the prior arrangements, thereby enabling such devices more readily accessible to the machine operator.
In fact it has been found that these devices can be readily serviced by an operator standing on a two-step trolley instead of a three-step trolley as was previously required, whilst large diameter take-up packages, of up to 30 can still be produced. This represents a considerable saving of effort for the operator over a working day and consequently improves operating efficiency.